Antinociceptive Effects Of Pretreatment Of Flurbiprofen Alex On Acute Pain In Rat And Its Central Mechanism

Objective To observe the preemptive analgesic effect by administrating pretreatmently flurbiprofen axetil to rats with incisional pain.Methods Animal model was made according to the Brennan method.Experimental rats were randomly divided into two main groups:P and C,each containing four subgroups,which were saline,flurbiprofen axetil 1 mg·kg^-1,3 mg·kg^-1,9 mg·kg^-1, repectively.Group P received saline or flurbiprofen axetil before incision and Group C 15 minutes after incision through tail vein.Calculative pain scorce test and hot plate test were performed at 2 h,24 h and 48h.Results For both group P and C, flurbiprofen axetil(1,3,9 mg·kg^-1)produced significant dose-dependent antinociception.The value of ED₅₀was 3.85 mg·kg^-1and 4.20 mg·kg^-1respectively. Confident intervals were(3.42,4.28)mg·kg^-1and(3.96,4.44)mg·kg^-1, respectively.Antinociception score and plantar withdrawl latency of group P were less than group C at 2 h,24h and 48h(p＜0.05).Conclusions The administration of flurbiprofen axetil through tail vein can produce dose-denpedent antinociception. Flurbiprofen axetil has showed preemptive analgesic effect. Objective To investigate the possible central mechanism occurring in the preemptive analgesic effect of pretreatment of flurbiprofen axetil on incisional pain in rats.Methods Animal model was made according to the Brennan method. Experimental rats were randomly divided into two main groups:P and C,each containing four subgroups,which were saline,flurbiprofen axetil 1 mg·kg^-1,3 mg·kg^-1,9 mg·kg^-1,repectively.Group P received saline or flurbiprofen axetil before incision and Group C 15 minutes after incision through tail vein.The phosphorylational levels of ERK1/2 in spinal dorsal horne in rats were detected semiquantatively by immunohistochemistry technology binding with the software Image-pro-plus 6.0,by biochemistry technology such as SDS-PAGE and Western blot. Results with comparison to both C₃ and C₉,the decreased amount of p—ERK expression occurring in spinal dorsal home in rats in the tow groups,P₃ and P₉ assumed significant difference(P＜0.05,n=8).Conclusions These results suggested that the down-regulation of p—ERK protein expression in spinal dorsal horne might be involved in the procedure of the preemptive analgesic effect by administrating pretreatmently flurbiprofen axetil to rats with incisional pain.